Due to the voltage divider on the HPD line, the HDMI connector on
imx6q-sabrelite doesn't reliably detect connected DVI monitors.
This patch allows to use the RX_SENSE signals as a workaround when
enabled by a boolean device tree property 'hpd-unreliable'.
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
drivers/gpu/drm/bridge/dw-hdmi.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
index 2388a55..7ffaa44 100644
--- a/drivers/gpu/drm/bridge/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/dw-hdmi.c
@@ -111,6 +111,7 @@ struct dw_hdmi {
struct device *dev;
struct clk *isfr_clk;
struct clk *iahb_clk;
+ bool hpd_unreliable;
struct hdmi_data_info hdmi_data;
const struct dw_hdmi_plat_data *plat_data;
@@ -1413,6 +1414,8 @@ dw_hdmi_connector_detect(struct drm_connector *connector,
bool force)
{
struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
connector);
+ /* If HPD is not reliable, use RX_SENSE as fallback */
+ u8 stat_mask = hdmi->hpd_unreliable ? HDMI_PHY_RX_SENSE : HDMI_PHY_HPD;
mutex_lock(&hdmi->mutex);
hdmi->force = DRM_FORCE_UNSPECIFIED;
@@ -1420,7 +1423,7 @@ dw_hdmi_connector_detect(struct drm_connector *connector,
bool force)
dw_hdmi_update_phy_mask(hdmi);
mutex_unlock(&hdmi->mutex);
- if (hdmi_readb(hdmi, HDMI_PHY_STAT0) & HDMI_PHY_HPD)
+ if ((hdmi_readb(hdmi, HDMI_PHY_STAT0) & stat_mask) == stat_mask)
return connector_status_connected;
/* free previous EDID block */
@@ -1556,7 +1559,7 @@ static irqreturn_t dw_hdmi_hardirq(int irq, void *dev_id)
static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
{
struct dw_hdmi *hdmi = dev_id;
- u8 intr_stat, phy_int_pol, phy_pol_mask, phy_stat;
+ u8 intr_stat, intr_mask, phy_int_pol, phy_pol_mask, phy_stat;
intr_stat = hdmi_readb(hdmi, HDMI_IH_PHY_STAT0);
phy_int_pol = hdmi_readb(hdmi, HDMI_PHY_POL0);
@@ -1583,9 +1586,12 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
* other end of the link. Use this to decide whether we should
* power on the phy as HPD may be toggled by the sink to merely
* ask the source to re-read the EDID.
+ * If HPD is known to be unreliable, ignore it completely.
*/
- if (intr_stat &
- (HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD)) {
+ intr_mask = hdmi->hpd_unreliable ?
+ HDMI_IH_PHY_STAT0_RX_SENSE :
+ HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD;
+ if (intr_stat & intr_mask) {
mutex_lock(&hdmi->mutex);
if (!hdmi->disabled && !hdmi->force) {
/*
@@ -1594,14 +1600,14 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
*/
if (!(phy_stat & HDMI_PHY_RX_SENSE))
hdmi->rxsense = false;
-
/*
* Only set the software rxsense status when both
* rxsense and hpd indicates we're connected.
* This avoids what seems to be bad behaviour in
* at least iMX6S versions of the phy.
*/
- if (phy_stat & HDMI_PHY_HPD)
+ else if ((phy_stat & HDMI_PHY_HPD) ||
+ hdmi->hpd_unreliable)
hdmi->rxsense = true;
dw_hdmi_update_power(hdmi);
@@ -1617,8 +1623,7 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
}
hdmi_writeb(hdmi, intr_stat, HDMI_IH_PHY_STAT0);
- hdmi_writeb(hdmi, ~(HDMI_IH_PHY_STAT0_HPD | HDMI_IH_PHY_STAT0_RX_SENSE),
- HDMI_IH_MUTE_PHY_STAT0);
+ hdmi_writeb(hdmi, ~intr_mask, HDMI_IH_MUTE_PHY_STAT0);
return IRQ_HANDLED;
}
@@ -1679,6 +1684,7 @@ int dw_hdmi_bind(struct device *dev, struct device
*master,
struct device_node *ddc_node;
struct dw_hdmi_audio_data audio;
struct dw_hdmi *hdmi;
+ u8 intr_mask;
int ret;
u32 val = 1;
@@ -1770,6 +1776,8 @@ int dw_hdmi_bind(struct device *dev, struct device
*master,
initialize_hdmi_ih_mutes(hdmi);
+ hdmi->hpd_unreliable = of_property_read_bool(np, "hpd-unreliable");
+
ret = devm_request_threaded_irq(dev, irq, dw_hdmi_hardirq,
dw_hdmi_irq, IRQF_SHARED,
dev_name(dev), hdmi);
@@ -1801,8 +1809,10 @@ int dw_hdmi_bind(struct device *dev, struct device
*master,
goto err_iahb;
/* Unmute interrupts */
- hdmi_writeb(hdmi, ~(HDMI_IH_PHY_STAT0_HPD | HDMI_IH_PHY_STAT0_RX_SENSE),
- HDMI_IH_MUTE_PHY_STAT0);
+ intr_mask = hdmi->hpd_unreliable ?
+ HDMI_IH_PHY_STAT0_RX_SENSE :
+ HDMI_IH_PHY_STAT0_RX_SENSE | HDMI_IH_PHY_STAT0_HPD;
+ hdmi_writeb(hdmi, ~intr_mask, HDMI_IH_MUTE_PHY_STAT0);
memset(&pdevinfo, 0, sizeof(pdevinfo));
pdevinfo.parent = dev;
--
2.6.4
